In beta 42, no layout is shown on View button by default, because “Hide Built-In Layout in Menus” is on.
In addition, it was difficult for me to find the option. The option is only mentioned in the manual of mac version. Moreover, setting icon of layout management panel in windows version is dots icon instead of gear icon which is mentioned in section 12.3 of windows version manual.
This is deliberately disabled by default at the moment, as the Layouts are not fully functional as designed. You can manually check the option and show them in the button.
Thank you for your quick response. I understood the situation.
RC 16
I came across Built-In Layouts when discussing with a Mac user but was disappointed not to see them included in the Windows version. Furthermore, the only reference I found to them in the Manual is in Appendix A.10.
When I looked in the Windows> Layouts I didn’t find any built-in layouts which confirmed my disappointment. But while exploring what was in the Layouts Manager and clicking on the three dots button to check options, I found that a ‘hide built-in layouts’ button was checked by default in RC16.
Unchecking this did cause the seven built-in layouts to be visible in the Views button on the Main Toolbar. Trying these out was not a delightful experience - I’m not sure they are operating as designed. And then I found this old thread from last year.
So, question for tiho_d: are they still hidden by default because they are not ready yet?
Other problem found while searching the manual for layout s info: the manual refers in A.10 and in 12.3.4 to File> Reveal … folders WHEN the actual text in the gui uses SHOW instead of REVEAL.
Thanks for the note on the wording of the menu command in the manual, I’ve fixed that.
As to the rest, yes as you note they are still in a rough state, which is why they are undocumented and kept out of the way for now. There will be an appendix added that explains them, once they are done.
Please note that in the release version I bought today, the default layouts are still hidden by default. After finding this thread, I un-hid them and they seem to work fine now, at least for me.
As you feature them in the - em - feature list, it might be a good idea to give them a little limelight? 
Edit: On second thought, I had saved my latest prefs from beta and imported them before checking for the layouts - maybe that’s why they were hidden?
Yes, nothing has changed with them in the past 56 days or so. Getting this feature finalised was deferred for post 3.0 launch.
Which feature list is this?